Rizo was a Bajoran male and father to Petra. In 2370, he led the hijacking of the Phoenix. By this time he had become mentally unstable. When Jadzia Dax attempted to regain control of the tanker using subterfuge, Rizo discovered who she really was. He managed to stun her, but soon the tables were turned when he was knocked unconcious by Odo. When he came to, he babbled on about ghosts on ship. He was later confined to a cargo bay on the tanker. Shortly after being confined, Petra was discovered to have hidden aboard the ship. After Dax and Odo found them together, Dax told Petra she could stay with her father in the cargo bay. Later, when the tanker was attacked by Cardassian fighters, Dax asked Rizo for his help in stopping them. He assisted, but soon turned on Dax. However, she managed to reason with him and he surrendered.
During the Occupation of Bajor, he was a farmer until the Cardassians took Petra's mother. Even though he asked around, he never found out what happened to her, but assumed that the Cardassians raped her to death. After her disappearance, he ran away with Petra and joined the Bajoran Resistance. Two days later he killed his first Cardassian. (DS9 novel: Antimatter)